UV photodissociation dynamics of HN3 in 190-248 nm

The H+N-3 channel in the ultraviolet photodissociation of HN3 has been investigated from 190 run to 248 nm using the high-n Rydberg H-atom time-of-flight technique. Product translational energy distributions as well as product angular anisotropy parameters were determined for the H+N-3 channel at different photolysis wavelengths. N-3 vibrational state distribution has also been derived from the product translational energy distribution at these wavelengths. Above photolysis wavelength 225 nm, HN3 predominantly dissociate through the repulsive state. Below 225 nm, a new slow channel starts to appear at 220 nm in addition to the existing channel. This channel is attributed to a ring closure dissociation channel to produce the cyclic N-3 product. As photolysis energy increases, this new channel becomes more important